Definition of Trimethylaminuria (TMA)

Trimethylaminuria (TMA): An inborn error
of metabolism associated with an offensive body odor, the smell of rotting fish, due to
the excessive excretion of TMA in urine, sweat, and breath. Persons with TMA may
experience tachycardia (fast heart rate) and severe hypertension (high blood pressure)
after eating cheese (which contains tyramine) and after using nasal sprays containing
epinephrine. TMA is caused by a mutation (change) in the gene for an enzyme,
flavin-containing monooxygenase-3 (FMO3) encoded by a gene on chromosome #1. The FMO3
enzyme metabolizes tyramine (which is in cheese). The syndrome is associated with various
psychosocial reactions, including social isolation, clinical depression and attempted
suicide.